High fibre, high protein diet for me.
I did them for about 18 months, and I honestly think that they work. I did lose weight, but more than that, I looked and felt more toned. Apparantly, they also reduce fat around your internal organs which is obviously really good.
I had to stop because as you've said, they're not cheap. It might be psychological, but I've definitely lost some muscle tone since I quit.
I've looked into it. It based around the idea that humans were basically designed to be hunter gatherers and that since we invented agriculture we eat too many grains and sugars.
I can tell you now, if you like chocolate this one isn't for you haha. The long and short of it is that you shouldn't eat anything that you couldn't gather, hunt or fish.
It's pretty much like any diet. If you reduce your calories (which you would on this diet) and move more, you'll lose weight.